HD 49798: Its History of Binary Interaction and Future Evolution

The bright subdwarf-O star (sdO), HD 49798, is in a 1.55 day orbit with a compact companion that is spinning at 13.2 seconds. Using the measurements of the effective temperature ($T_{\rm eff}$), surface gravity ($\log g$), and surface abundances of the sdO, we construct models to study the evolution of this binary system using Modules for Experiments in Stellar Astrophysics ($\texttt{MESA}$). Previous studies of the compact companion have disagreed on whether it is a white dwarf (WD) or a neutron star (NS). From the published measurements of the companion's spin and spin-up rate, we agree with Mereghetti and collaborators that a NS companion is more likely. However, since there remains the possibility of a WD companion, we use our constructed $\texttt{MESA}$ models to run simulations with both WD and NS companions that help us constrain the past and future evolution of this system. If it presently contains a NS, the immediate mass transfer evolution upon Roche lobe (RL) filling will lead to mass transfer rates comparable to that implied in ultraluminous X-ray sources (ULXs). Depending on the rate of angular momentum extraction via a wind, the fate of this system is either a wide ($P_{\rm orb}{\approx} 3$ day) intermediate mass binary pulsar (IMPB) with a relatively rapidly spinning NS (${\approx} 0.3$ s) and a high mass WD (${\approx} 0.9 M_\odot$), or a solitary millisecond pulsar (MSP).Comment: 6 pages, 4 figure

Concert recording 2015-04-10

[Track 01]. Neun deutsche Arien, HWV 202 & 209. Künft\u27ger Zeiten eitler kummer, no. 1 ; [Track 02]. In den angenchmen Büschen, no. 8 / George F. Handel -- [Track 03]. Vorrei spiegarvi, oh Dio! K. 418 / Wolfgang A. Mozart -- [Track 04]. Chanson perpétuelle op. 37 / Ernest Chausson -- [Track 05]. L\u27invitation au voyage / Henri Duparc -- [Track 06]. La diva de l\u27empire / Erik Satie -- [Track 07]. Der Hirt auf dem Felsen D. 965 / Franz Schubert

Concert recording 2015-04-10

[Track 01]. Neun deutsche Arien, HWV 202 & 209. Künft\u27ger Zeiten eitler kummer, no. 1 ; [Track 02]. In den angenchmen Büschen, no. 8 / George F. Handel -- [Track 03]. Vorrei spiegarvi, oh Dio! K. 418 / Wolfgang A. Mozart -- [Track 04]. Chanson perpétuelle op. 37 / Ernest Chausson -- [Track 05]. L\u27invitation au voyage / Henri Duparc -- [Track 06]. La diva de l\u27empire / Erik Satie -- [Track 07]. Der Hirt auf dem Felsen D. 965 / Franz Schubert

Intra-Individual Variability in Vagal Control Is Associated With Response Inhibition Under Stress

Dynamic intra-individual variability (IIV) in cardiac vagal control across multiple situations is believed to contribute to adaptive cognition under stress; however, a dearth of research has empirically tested this notion. To this end, we examined 25 U.S. Army Soldiers (all male, mean age = 30.73, standard deviation (SD) = 7.71) whose high-frequency heart rate variability (HF-HRV) was measured during a resting baseline and during three conditions of a shooting task (training, low stress, high stress). Response inhibition was measured as the correct rejection (CR) of friendly targets during the low and high stress conditions. We tested the association between the SD of HF-HRV across all four task conditions (IIV in vagal control) and changes in response inhibition between low and high stress. Greater differences in vagal control between conditions (larger IIV) were associated with higher tonic vagal control during rest, and stronger stress-related decreases in response inhibition. These results suggest that flexibility in vagal control is supported by tonic vagal control, but this flexibility also uniquely relates to adaptive cognition under stress. Findings are consistent with neurobehavioral and dynamical systems theories of vagal function

Branding and a child’s brain: an fMRI study of neural responses to logos

Branding and advertising have a powerful effect on both familiarity and preference for products, yet no neuroimaging studies have examined neural response to logos in children. Food advertising is particularly pervasive and effective in manipulating choices in children. The purpose of this study was to examine how healthy children’s brains respond to common food and other logos. A pilot validation study was first conducted with 32 children to select the most culturally familiar logos, and to match food and non-food logos on valence and intensity. A new sample of 17 healthy weight children were then scanned using functional magnetic resonance imaging. Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex. Compared to non-food logos, food logos elicited increased activation in posterior cingulate cortex. Results confirmed that food logos activate some brain regions in children known to be associated with motivation. This marks the first study in children to examine brain responses to culturally familiar logos. Considering the pervasiveness of advertising, research should further investigate how children respond at the neural level to marketing